Flotation treatment of sylvinite



Patented Mar. 16, 1954 FLOTATION TREATMENT OF SYLVINITE Arthur J. Weinig, Golden, 0010., assignor to Potash Company of America, 'a corporation of Colorado No Drawing. Application "April 16, 1948, Serial No. 21,542

3 Claims.

This invention, which is a continuationin part of my application "SerialNo. 582,574, new abandoned, relates to the froth flotation treatment of sylvinite ore or similar compositions, such as the sylviniteores from the Carlsbad, New Mexico deposit, and more particularly relates to treatments for recovering the sylv'iteconten't of such ores as a froth concentrate.

Following the discovery that the soluble constituents of these ores could be separated by froth flotation, many "processes were developed to perform such operations economically. In'my earlier Patent No. 2,188,932, I have disclosed a procedure in which the sylvite is collected as a froth concentrate, and thereafter both the froth and residue of the separation are subjected to secondary treatments to produce finally a substantial-lycomplete recovery of the sylvite content.

In preparing the ore for treatment, the ore is ground to reduce it to a suitable flotation size and also to obtain a physical separation between the K01 and "NaCl particles. These minerals frequently do not unlock until they reachquite fine size ranges, and consequently if al lthe'ore is ground to such a fine size (-100 mesh, for example) an undue amount of slimes is produced due to the relatively soft character of the mineral.

Usually the ground ore is deslimed and mixed with a brine saturated with respect to the soluble ore-components to form a pulp. Collector reagents are added, and the pulp then subjected to froth flotation to separate the potassium salts.

If it is desired to concentrate the potassium salts in the froth, and lead or bismuth ions are not present in the brine, collector reagents usually referred to as octadecyl amines may be employed. In this class of collector reagents I include primary aliphatic amines having fr om 6 to 18 or 20 carbon atoms, such as those disclosed in U. S. patent No. 2,287,274. More specifically, I refer to a group of reagents incorporating the -(CH2) l6CH2- radical, such as:

Potassium double salt CH3 (CH2) 1eCHz-NHz-KCI Noncecylic acid CH:;(CH2)15CH2COOH Alkali metal soaps, such as CH3(CH2)16CH2C'OOK These reagents are in general limited as tothe degree or speed of solution in water and brine, and are'greatly reduced inefficiency by the presence of slimeswhich appear to neutralize at least partially these reagents, and adversely affect their selectivity.

It is an object of the present invention to provide a simple, economical and 'efii'cient process for concentrating the sylvite content ofsylvinite ores in operations utilizing octadecyl amine reagents.

Another object of this invention is to provide areagent additive which will reduce reagentconsumption in the flotation of the sylvite "content of slime-containing sylvinite ore pulps.

Further objects of my invention include the provision of a modifier reagent for the froth flotation of sylvinite ore which, in addition to functioning as a frother, serves to change the character of the froth produced by the collector reagent employed, which is an excellent solvent for aliphatic amine reagents and which does not require complete desliming operation.

Other objects reside in various novel steps and treatments and combinations thereof as subsequently described in detail.

'In brief, I have discovered that the action ofthe octadecyl amine and'related collector reagents'can be'greatly improved 'by dissolving the reagents in a chlorinated 'aminated mixture of liquid hydrocarbons, such as'may be obtained by reacting a kerosene with chlorineand ammonia. This not only greatly increases the selectivity andefficiency of the reagent, but also improves the character "of "the froth "and substantially eliminates the sensitivity of amine reagents to slimes.

As disclosed in my application, Serial No. 21,541, a. continuation in part of my application Serial No. 582,573, now abandoned, this liquid hydrocarbon mixture, or DAK, as it is commercially designated, is a highly eiiicient collector reagent for sylvite if lead or bismuth ions are present in the pulp, its characteristics and production being described in said applications in detail and incorporated herein by reference. Broadly, DAK is prepared by aminating and chlorinating a relatively unsaturated kerosene or similar distillate, such as that obtained from Mt. Pleasant, Michigan crudes, by conventional processes. The non-amino content is removed by treatment with mineral acid, resulting in a liquid mixture of hydrocarbon solvents containing 0.90%-29.0% chlorine and 544% nitrogen in which primary amines are apparently more predominant than the secondary or tertiary amines. Processing is continued until the composite molecular weight as determined by the freezing point method is between 190 and 280, preferably about 240. Apparently the lower boiling point fractions of this mixture are the most efficient collector compounds and tend to include compounds of relatively low chlorine content, as for example 0.90%-8.0% chlorine which are therefore to be preferred. As used, the mixture is mildly alkaline in nature, requiring 0.2 part of HCl for neutralization, and has an iodine value of about 70.

By way of illustration, DAK, manufactured by The Mathieson Alkali Works was tested and found to be an excellent solvent for the following amine reagents of Armour and Company: AMAC 1180 C and AMCL 1180 C. The former has a solubility in DAK of at least 40 grams per 100 cc. DAK at 180 F. This reagent is a mixture of monohexadecyl and monooctadecyl amine acetate having 18 carbon atoms and of technical grade. AMCL 1180 C is an amin hydrochloride having 18 carbon atoms, less soluble in DAK, but showing a decided tendency to float KCl.

Two typical test operations will illustrate the advantages of the use of such reagents. In the first of these tests, Carlsbad sylvinite ore was ground to -35 mesh, and was introduced into a saturated solution of the'ore in the proportion of one part ore to four parts brine. No desliming was done on the head ore and the reagent taken for the test comprised 1.4 lb. DAK and .3 lb. AMAC per ton of head ore. A simple flotation treatment was performed and the results follow:

Percent Percent Percent Wt. K 1 Parts Rec.

Cleaner Concentrate... 25.0 96.0 24. 60 Cleaner tails 19. 73. 9 l4. 4 36 Roughor tailing 55. 5 2. 7 1.7 4 Total 100. 0 40. l 100 pulp was filtered and the clear filtrate was added to the cleaner concentrate. The whole lot then was cooled to the initial temperature, namely, 72 F. In this heat treatment, the K01 dissolved in the tailings is precipitated and recovered with the flotation concentrate. The results follow:

Percent Percent Percent Wt. K01 Recovery Final concentrate 40. 8 98. 2 99. 9 Final tailings 59. 2 0. 0

From the foregoing examples it will be ap- 4 parent that a highly efficient flotation separation can be obtained, even when the pulp contains a relatively large quantity of slimes sizes. This is of considerable value over operations previously in use in the art in that all the ground product can be treated effectively instead of employing a slimes separation on ahead of flotation with consequent loss of the KCl content of the slimes reject product.

While the practice of the present invention is particularly adapted to the treatment of sylvinite ores, it also is applicable to other pulps such as sodium chloride-potassium chloride mixtures obtained by solar evaporation of saline waters such as the Utah salt deposits, or other potash-bearing ores such as mixtures of polyhalite and sylvite or langbeinite and sylvite.

Therefore, the foregoing examples are intended merely as typical examples of the present invention, but are not intended to limit the same. the scope of the invention having been fully set forth in the hereunto appended claims.

I claim:

1. In a froth flotation treatment of sylvinite ores and the like in which the K01 content is subjected to the action of a reagent of the class of octadecyl amines and reaction products thereof, the improvement which comprises dissolving said reagent in a chlorinated aminated mixture of liquid aliphatic hydrocarbons and surface coating the KCl particles with the resulting solution.

2. The froth flotation process which comprises forming a pulp by introducing a K01 containing ore, inclusive of slime sizes, into a solution saturated with respect to KCl, subjecting the pulp to a froth flotation treatment in the presence of an amine collector reagent having more than 6 and less than 21 carbon atoms therein and preventing said slimes from neutralizing the reagent by adding a chlorinated aminated mixture of liquid aliphatic hydrocarbons to the pulp.

3. The froth flotation process which comprises forming a pulp by introducing sylvinite ore inclusive of slime sizes into a saturated sodium chloride-potassium chloride solution, subjecting said pulp to a froth flotation treatment in the presence of an octadecyl amine collector reagent, and preventing said slimes from neutralizing the reagent by dissolving said reagent in a chlorinated aminated kerosene solvent before introducing it into the pulp.

ARTHUR J. WEINIG.

References Cited in the file of this patent UNITED STATES PATENTS Clark Oct. 31, 1944 

1. IN A FROTH FLOTATION TREATMENT OF SYLVINITE ORES AND THE LIKE IN WHICH THE KCL CONTENT IS SUBJECTED TO THE ACTION OF A REAGENT OF THE CLASS OF OCTADECYL AMINES AND REACTION PRODUCTS THEREOF, THE IMPROVEMENT WHICH COMPRISES DISSOLVING SAID REAGENT IN A CHLORINATED AMINATED MIXTURE OF LIQUID ALIPHATIC HYDROCARBONS AND SURFACE COATING THE KCL PARTICLES WITH THE RESULTING SOLUTION. 